Microelectromechanical systems (hereafter “MEMS”) are a type of microstructure devices. Current MEMS devices often employ deformable or flexible elements (hereafter “deformable elements”) to achieve desired functions. A MEMS device having a deformable element, however, may suffer from performance degradation and even device failure when the deformable element of the MEMS device experiences accumulation of permanent deformation during operation, especially during repeated actuation or deformation of the deformable element in operation. For example, a micromirror device with a torsional hinge may establish therein permanent deformation during state transitions; and the permanent deformation can be accumulated through repeated actuation. As a consequence, the accumulated deformation, which is also referred to as “deformation memory” or “memory properties” can bias the designed operational states of the micromirror device—resulting in performance degradation and even device failure. This same type of accumulated memory can occur in many other types of MEMS devices besides the exemplary micromirrors having torsional hinges.
Therefore, what is needed is a method to minimize or eliminate memory accumulation in deformable elements of a MEMS device without substantially sacrificing the deformation ability of the deformable element of the device.